[Affected versions]: - Latest Nightly 60.0a1 (2018-02-05) [Affected platforms]: - Windows 7 x86 Preconditions Fx build with WebAuth enabled USB hardware key [Steps to reproduce]: 1.Insert USB hardware key 2. Go to this site: https://webauthn.bin.coffee/ 3. Touch USB hardware key, and quickly click on button labeled "Create Credentials". [Expected result] Debug output on page should prompt you to perform verification. [Actual result] Debug output on page should indicate successful credential creation. [Note]: - On windows 7: Even after waiting for 8 sec after touching the USB hardware key, and them clicking on the labeled button "Create Credentials" the debug output on page should indicate successful credential creation. - On Ubuntu 16.04: Only after waiting for 2 sec the same issue occurred. - There were no problems on windows 10 x64 and on Mac OS X 10.12.

This only happen using the large USB Token with the button.

So is the issue here that the YubiKey is touched before Firefox starts polling, and then the non-Nano YubiKey seems to successfully register because it was recently touched?

There weren't any issues using the non-Nano YubiKey. The issue appears while using "ST fido-01-321" USB with a button on it following the steps described in the description.

I can't reproduce this with any of my varied Feiten, DigiPass, Plug-Ups, U2F Zero, or Yubico devices. I think it's probably just this one token, so I'm going to resolve this worksforme. Please re-open if we see it happen with other devices.